Set during the Sengoku period, beyond deeply snow-covered mountain passes, lies the land of Ashina. Wolf is a master shinobi, taken in from the battlefields of Ashina and rigorously trained in the ninja arts. The young boy he serves, Kuro, is the descendant of an ancient clan possessing a special bloodline known as the "Dragon's Heritage." Bound together, they exist as a solitary lord and retainer with nowhere else to turn.
The blood of the Dragon's Heritage possesses the power to grant immortality. While fleeing from the Ashina samurai who seek to claim this power, Wolf and Kuro uncover a dark truth: in exchange for immortality, the Dragon's Heritage spreads a fatal disease known as "Dragonrot" among the populace. Searching for a way to cure the plague, Kuro learns it can only be achieved at the cost of his own life. After much agonizing deliberation, he resolves to sever the ties of immortality once and for all.
Meanwhile, upon discovering the heavy resolve his master has kept hidden, Wolf embarks on a grueling, solitary battle to alter Kuro's tragic fate—
